Bill is fearful of most social situations, whereas Andrea is only fearful of giving speeches. Given this, one could infer that

Bill's fear began at an earlier age.

Bill may be more likely to abuse alcohol.

Andrea has less impairment.

Explanation:

As per the question above, Bill is experiencing social phobia whereas Andrea is experiencing specific phobia.

Social phobia: In abnormal psychology, the term social phobia is also denoted as "social anxiety disorder" and is described as one of the types of anxiety disorder that leads to developing extreme fear in any social setting or gathering. An individual who is experiencing social phobia has trouble while talking to people, attending social settings, and meeting new people. He or she fears of being scrutinized by someone else.

Specific phobia: It is described as an individual's irrational & intense fear of something that consists of little or no relevant danger. It develops severe anxiety in individuals experiencing it.

experiments.

surveys.

questionnaires.

interviews.

case studies.

participant and non-participant observation.

observational trials.

studies using the delphi method.

answer; a group made up of people from difference cultures;